It is a known desire to monitor cell characteristics such as cell voltage and cell temperature of individual cells connected in series to form a battery such as a lithium ion battery pack used in a vehicle. Such monitoring may help to maximize performance and/or reliability of the battery. It has been suggested to equip each cell with an integrated circuit that measures cell voltage and communicates that information onto a communication network. However, each integrated circuit requires a high precision voltage reference, and must be configured to interface the potentially high absolute voltage of cells at the top of the stack of cells forming the battery with the relatively low voltages present on a communication network. Such requirements tend to undesirably increase the cost of the integrated circuit and so undesirably increase the cost of a battery monitoring system.